• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.6-8
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• 2005

The forest soils of 92 sites in Korea were analyzed to survey heavy metal background levels using aqua regia digestion method and 0.1N HCl extraction method. From these results, the average natural contents of heavy metals were Cd 0.287, Cu 15.26, Pb 18.43, Cr 25.36, Zn 54.27, Ni 17.68mg/kg for aqua regia method, and Cd 0.040, Cu 0.48, Pb 3.06, Cr 0.09, Zn 1.54, Ni 0.27mg/kg for 0.1N HCl extraction method. The range of correlation coefficients between heavy metal contents obtained from two methods(aqua regia and 0.1N HCl) was significant as $0.24{\sim}0.88$, and the correlation coefficients were decreased in order of Cd, Pb, Cu, Ni, Cr, Zn.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.63-70
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• 2014

This paper describes the influence of rainfall on contamination at stream around the developed quarry. The investigation results are analyzed to evaluate the relationship rainfall and heavy metals (or water pollution). In the relationship rainfall and heavy metals, the result showed that the heavy metal contaminations are caused by boulder stone, waste residue and stone sludge, which is reacted with the direct contamination source, in the burried layer. It also found that the water flow change of stream according to the rainfall increase affected the large effect to a contamination level of heavy metal. the water pollution was increased by time changed from the rainy season to the dry season. That is, a lot of suspended solids had been discharge from the developed quarry due to rainfall increase, and then pollution level of water increases as the undercurrent of suspended solids is generated in stream due to rainfall decrease. Therefore, it analyzed that continuous causes of heavy metal contamination and water pollution in stream are materials in the burried layer and a discharge of pollution source from the developed quarry due to rainfall.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.22-29
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• 2000

This study was performed to investigate the concentrations of TSP, PM10 and heavy metals(Pb, Cd,Hg, Ni, Zn) of underground parking lots in Taegu city. The samples were collected from 3 department stores and 1 central park in the winter and the summer, 1997. The samples of 3 department stores were divided into sale period and non-sale period in the winter and the summer. The concentrations of TSP and PM10 were 109.6±1.5㎍/㎥ and 93.3±1.5㎍/㎥. In TSP, the zinc was the highest level, 287.16±1.5ng/㎥ and the cadmium was the lowest, 2.4±2.1ng/㎥ and in PM10, the zinc was the highest level, 193.6±1.5ng/㎥ and the cadmium was the lowest, 0.6±3.9ng/㎥. The correlation coefficient between the concentration of TSP and PM10 was 0.982(p<0.05). The correlation coefficients of corresponding heavy metal in TSP and PM10 were 0.863 for lead, 0.617 for mercury, 0.890 for nickel and 0.850 for zinc(p<0.05). The concentrations of TSP, PM10 and cadmium of PM10 in the winter were higher than those of the summer. However, the concentration of Hg of PM10 in the summer was higher than that of the winter. The concentrations of TSP and PM10 in sale period was higher than those of non-sale period and the concentrations of heavy metal in TSP and PM10 were not significantly different between sale and non-sale period. The proportions of PM10 to TSP were above 60% in dust, lead, nickel, and zinc and less than 40% in cadmium and mercury. The concentrations of TSP, PM10 and heavy metal in the underground parking lots were comparatively lower than those of general atmosphere. However, this kind of research to PM10 in the underground parking lots must be continued because it is very important particulate matter that affects human beng's health.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.5
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• pp.724-734
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• 2019

This study selected a representative small arm firing range and analyzed the distribution of heavy metal pollutants such as Pb, Cu, Zn, etc. For this the concentrations of heavy metals in soils, roots and leaves of plants, and water of the small arm firing range were measured. The concentrations of heavy metals in the effluent were also checked during precipitation. The concentration of lead in the samples collected from the top soil(0-5 cm) and sub soil(5-50 cm) near the target in the small arm firing range exceeded the concern level of the Soil Environment Conservation Act of Korea, but not in other soil samples. Plants that grow in soil heavily contaminated with lead showed a high lead concentration, especially in roots. However, the concentration of lead in effluent from the small arm firing range was less than 0.02 ppm. The concentration of copper and zinc in the small arm firing range did not surpass the concern level of the Soil Environment Conservation Act of Korea. Through this study more accurate information on the distribution of heavy metal pollution in the soil of the small arm firing range was obtained. Based on this research, we can conclude that some facility improvements can reduce the spreading of pollutants in the currently used small arm firing range and contribute to the design and operation of advanced small arm firing ranges.

• Korean Journal of Ecology and Environment
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• v.43 no.3
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• pp.377-384
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• 2010

Heavy metal accumulation levels of inhabitant fish, Hemibarbus labeo in Andong and Imha reservoirs were analyzed using an inductively coupled plasma spectrometer and atomic absorption spectrometer. Heavy metal contents of H. labeo from Andong reservoir were higher than those from Imha reservoir. Likewise, relative high contents of As, Cd and Hg were detected in the tissues from Andong reservoir. Among the heavy metals, Al, As and Fe were detected with high concentration in the gill tissues but not in the muscle tissues. Also, the average content of Zn was almost similar in all tissues. In addition, high accumulated level of Al, Cr, Cu and Mn were detected in gill and kidney tissues of H. labeo from Andong reservoir. As a result, the heavy metal contents from the inhabitant fishes, H. labeo, in Andong reservoir showed higher than those in Imha reservoir. We propose that heavy metal contamination in water and in inhabitated fishes is caused from various metals derived from water and sediments in water environment of Andong reservoir.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.487-493
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• 2017

Recent years have seen steadily increasing concerns about human exposure to heavy metals through seafood consumption. In Korea, the diverse dietary patterns of different bivalve shellfish necessitate tissue-specific evaluation of heavy metal contents for risk assessment. We analyzed the heavy metal contents of various tissues in scallops (Patinopecten yessoensis) and pen shells (Atrina pectinate). In both species, we found higher levels of cadmium (Cd) in the mantle than in the adductive muscle, while there was no significant difference between the two tissue types in total mercury (THg) and lead (Pb) (P<0.05). Levels of THg and Pb were acceptable by Korean standards. However, the level of Cd in pen shell mantle tissue exceeded the standard by 40%. The rate of heavy metal exposure from consumption of these species was shown to be 0.003-0.010% of the provisional tolerable weekly intake of THg and 0.312-0.600% of the provisional tolerable monthly intake (PTWI) of Cd as recommended by the Joint FAO/WHO Expert Committee on Food Additives. These findings on the tissue-specific heavy metal contents of these species will be useful in assessing the health risks of Korean dietary habits.

• Journal of Industrial Technology
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• v.16
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• pp.169-174
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• 1996

Microstructural analyses of synthetic arsenic-containing heavy metal sludges solidified with Portland cement were performed. Heavy metal sludges containing 0.04M of cadmium, chromium, copper, lead, and arsenic were prepared by sodium hydroxide precipitation and successive vacuum filtration. The sludges mixed with cement were cured for 14 days. The solidified sample was characterized by 1) leaching test, 2) scanning electron microscopy and 3) X-ray diffractometry. Of the metals tested, only Pb concentration in the leachate exceeded the Korean regulatory limit. The level of lead in the leachate was as high as 10 times the regulatory limit. X-ray analysis suggested that the metal hydroxides might be present in complex or impure crystalline phases.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.341-354
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• 2002

Heavy metal concentration/distribution in sediments and bivalves from the tidal flats in Saemankeum coastal area, western Korea, were investigated, Among 6 sampling sites, S2, S5 and S6 showed the higher levels of Zn, Cr, Ni, Cu and Cd contamination and S1 did the higher level of Pb contamination than other sites, while S-4 showed the lowest levels of these metal contamination. Overally, the levels of Zn, Cu and Pb concentrations in Sinonovacula constricta were estimated to be relatively high. The shell lengths of the collected mussels were linearly related to their dry weights of the whole soft parts, but the mussels collected from S3 were in a poor nutrition, resulting in the distinctively high levels of metal concentrations in the body. It was shown that in S. constricta, Cr, Ni, Cu and Zn are distributed equally into the whole soft parts or a little more into the flesh, after absorption, while Fe, Cd, Pb and Mn are transferred more into the non-flesh parts than into the flesh parts. In S. constricta, the heavy metal concentrations in the flesh increase with those in the whole soft parts. The bioaccumulation factors(heavy metal concentration in S. constricta/heavy metal concentration in sediment) showed that, of the examined metals, Cd is the most cumulative in the body of S. constricta, followed by Zn and Cu, while Mn, Cr, Ni and Pb are not cumulative.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.42-46
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• 2016

Hydrogen assisted cracking (HAC) is one of the most complicated problem in welding. Huge amount of studies have been done for decades. Based on them, various standards have been established to avoid HAC. But it is still a chronic problem in industrial field. It is well known that the main causes of the hydrogen crack are residual stress, crack susceptible micro structures and a certain critical level of hydrogen concentration. Even though the exact generating mechanism is unclear till today, it has been reported that the hydrogen level in the weld metal should be managed less than a certain amount to prevent it. Matsuda studied that the residual hydrogen level in the weld metal can be varied even if the initial hydrogen content is same. It is also insisted in this report that the residual hydrogen concentration is in stronger correlation with hydrogen crack than the initial hydrogen content. But, in practical point of view, the residual hydrogen is still hard to consider because measuring hydrogen level is time and cost consuming process. In this regard, numerical analysis is the only solution for considering the residual hydrogen content. Meanwhile, Takahashi showed the possibility of predicting the residual hydrogen by a rigorous FE analysis. But, few commercial software suitable for solving the weld metal hydrogen has been reported yet. In this study, two dimensional thermal - hydrogen coupled analysis was developed by using the commercial FE software MARC. Since the governing equation of the hydrogen diffusion is similar to the heat transfer, it is shown that the heat transfer FE analysis in association with hydrogen diffusion property can be used for hydrogen diffusion analysis. A series of simulation was performed to verify the accuracy of the model. For BOP (Bead-On-Plate) and the multi-pass butt welding simulations, remaining hydrogen contents in the weld metal is well matched with measurements which are referred from Kim and Masamitsu.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.529-531
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• 2003

In order to investigate the level of heavy metal contamination and the seasonal variation of metal concentrations in soils and sediments influenced by past mining activities, tailings, soil and sediment samples were collected from the Hwacheon mine in Korea. The main pollution sources in this mine site are suggested as tailings and mine waste rocks. Elevated levels of Cd, Pb and Zn were found in soils and sediments. In a study of seasonal variation on the heavy metals in soils and sediments, heavy metals were higher enriched collected from before rainy season ($2^{nd}$ sampling) than after rainy season ($1^{st}$ sampling). Also, in order to estimate the microbial effects on Cd speciation in sediments, bacteria which can adsorb Cd was isolated and Cd adsorption characteristics of isolated bacteria in Cd solution was evaluated. The Cd bioremoval efficiency in Cd solution (5 ppm) by bacteria was more than $90\%$. Bioremoval efficiency in single metal solution was higher than that in mixed metal solution of Pb and Zn.